This is a beginner level pattern that is cute. It is quick and easy to make, the instructions are aimed for a person how knows how to knit but might not have experience of knitting sweaters before.

Cardigan
Yarn: Heavy DK to worsted weight yarn, I used Abuelita 4 ply (100% merino wool, 250 meter/100 gram) for the undyed and Pickles Cash-Kid (85% cashmere, 15% kid mohair, 87.5 meter/25 gram) for the blue.
Yardage: 200(220, 240, 270, 300, 330, 360) meter
Gauge: 21 stitches/10 cm and 28 rows/10 cm in pattern stockinet and garter stitch on washed fabric worked back and forth. You may need to go down a needle size for the garter stitch edgings in order to get gauge.
Needles: 3.5 mm or size that gives you the gauge called for on washed fabric. I recommend that you have one 40-60 cm circular needle and dpns for the sleeves
Sizes: 56(62, 68, 74, 80, 86, 92) cm. The sizes refer to the length of the child according to European standards, see schematics for details. The sizes approximately correspond to age newborn(3, 6, 9, 12, 18, 24) months. Made to fit chest circumference: 41(43, 45, 47, 49.5, 52, 54) cm.
Ease: 6 cm positive ease to allow for easy dressing and a shirt underneath.
Buttons: 5(5, 6, 6, 6, 7, 7) 12-14 mm buttons.

Hat
Yarn: Heavy DK to worsted weight yarn, I used Abuelita 4 ply (100% merino wool, 250 meter/100 gram) for the undyed and Pickles Cash- Kid (85% cashmere, 15% kid mohair, 87.5 meter/25 gram) for the blue. Yardage: 50(60, 70, 80, 90) meter
Gauge: 21 stitches/10 cm and 28 rows/10 cm in pattern stockinet on washed fabric worked in the round and 26 stitches/10 cm for ribbing. Needles: 3.5 mm dpns or size that gives you the gauge called for on washed fabric. For the larger sizes I recommend a 40 cm circular needle in addition to dpns.
Sizes: 32(36, 40, 44, 48) cm preemie(newborn, baby, toddler, small child)
Ease: This pattern has no ease.